Recently, large-capacity and high-speed optical transmission systems have been developed. Although the related art systems transmit signals at speeds of 10 Gbps, systems transmitting signals at speeds of 40 Gbps, or even 100 Gbps have been developed intensively.
In the design for mounting electronic equipment, connecting a flexible printed circuit board and a module via a connecter is widely used for signal transmission therebetween. The flexible printed circuit board is a flexible and bendable printed circuit board which is widely used in, for example, small-sized products with limited mounting space.
An optical transmitter converts electrical signals into optical signals and an optical receiver converts optical signals into electrical signals. In a connecting portion where electrical/optical conversion or optical/electrical conversion is carried out, electrical signals are typically transmitted to a printed circuit board via the flexible printed circuit board. A transmission speed at the portion has been also increased.
Japanese Laid-open Patent Publication No. 2007-123183 has proposed a connector which connects a flexible printed circuit board and a printed circuit board. Japanese Laid-open Patent Publication No. 2006-189469 has proposed a connector which includes an optical/electrical converter.